When a sniper’s bullet struck Pfc. Colton Rusk, the first to reach his body was his best friend Eli – a bomb-sniffing, black Labrador so loyal he snapped at other Marines who rushed to his fallen handler.

The two were inseparable. Military dogs are supposed to sleep in kennels when deployed, but Rusk broke the rules and let Eli curl up with him on his cot. Other times, the dog took up the entire sleeping bag. Rusk ate ready-to-eat meals, so that’s what Eli ate instead of dog food, Darrell Rusk said.

“Whatever is mine is his,” Colton Rusk wrote on his Facebook page.

After Rusk died Dec. 6, his parents decided they wanted to adopt his dog. They picked Eli up Thursday at Lackland Air Force to take him back to their home in rural South Texas. It was only the second time that a U.S. military dog has been adopted by the family of a handler killed in combat.